June 25 (Reuters) - Major stock markets in the Gulf fell in early trade on Thursday, pressured by weaker oil prices and rising bets on U.S. interest rate hikes this year.

Oil prices - a catalyst for the Gulf's financial markets - extended their decline to near levels last seen before the start of the Iran war, as expectations of rising supply from the Middle East outweighed demand concerns.

An initial accord last week to end the U.S.-Israeli war with Iran, which began on February 28, has allowed the resumption of traffic through the Strait of Hormuz.

Saudi Arabia's benchmark stock index .TASI eased 0.3%, dragged down by a 0.5% fall in Saudi National Bank 1180.SE, the country's biggest lender by assets.

The Qatari index .QSI was flat in choppy trade.

High U.S. inflation, fuelled by the Iran war, and a hawkish Federal Reserve have contributed to expectations of rate hikes.

Traders expect three Fed rate hikes this year and are pricing in about a 67% chance of a September increase, according to the CME FedWatch Tool.

Monetary policy shifts in the U.S. have a significant impact on Gulf markets, where most currencies are pegged to the dollar.

Dubai's main share index .DFMGI lost 0.2%, pressured by a 1.2% drop in sharia-compliant lender Dubai Islamic Bank DISB.DU.

In Abu Dhabi, the index .FTFADGI was down 0.3%.